A humidity controlled air flow terminal device works as a humidity sensor : its openingsurface varies according to relative humidity inside a room in order to match air flow rate topollution. These components are fouling up when used during several months.In a laboratory, an air flow with a high rate of particules is fouling up five identical air devicesin a few hours. Considering a constant relative humidity, the impacts on two devices aresimilar : it seems that artificial fouling tests can be reproduced. These first tests show a highsensitivity to fouling at low relative humidities (small openings devices) and nearly nosensitivity at high relative humidities (large openings devices).The characteristic curve of a humidity controlled air flow device represents the air flow rate infunction of the relative humidity at a set pressure loss. The curves of four devices arecompared before and after the accelerated fouling : the most important absolute air flowreduction is about 3.1 11s. This maximum is always reached near the point of RH = 60 %. Thecorresponding relative reduction varies from 14 % to 23 %. The nearly same relativereductions are measured at the point of RH = 60 % with two years old fouled up devices fromreal dwellings although the fouling is visually very different. Thus, the accelerated artificialfouling experiments seem to be representative of real cases.
Experimental impact valuation of fouling on extract air terminal devices performances: an accelerated artificial fouling approach.
![](https://www.aivc.org/sites/default/files/default_images/default_image_5.png)
Year:
1998
Bibliographic info:
19th AIVC Conference "Ventilation Technologies in Urban Areas", Oslo, Norway, 28-30 September 1998